Guide · 3 min read
Spring Pre-Emergent: The One Application That Prevents a Season of Weeds
Spring pre-emergent is the single highest-leverage lawn care action of the year. Done well, it prevents crabgrass and most summer annual weeds before they ever appear.
Why timing matters
Pre-emergents work by intercepting seeds as they germinate. Apply too early and the barrier weakens before the weed pressure peaks; apply too late and the weeds are already up.
How to apply
Use a broadcast spreader at the labeled rate. Water in with 0.25–0.5 inches within 48 hours to activate the barrier.
What to expect
You won't see anything change. That's the point — the weeds you didn't get are the win.
Frequently asked
- Can I overseed after applying pre-emergent?
- No — pre-emergent will prevent grass seed from germinating too. Wait until fall to seed if you applied a spring pre-emergent.
- What if I miss the window?
- Skip the spring application and shift to post-emergent spot treatments as weeds appear. Get back on schedule next spring.
Turn knowledge into action
This guide explains the science behind this recommendation. LawnPlan applies these same principles automatically using your ZIP code, grass type, climate region, and biological timing to determine exactly when you should perform each task.
Build my personalized lawn plan →Your personalized plan — what to do and when — lives on your annual roadmap.